Dyanmic Skip Fire could bring a revolution to cylinder deactivation technology and boost fuel economy by around 15 percent. As opposed to shutting down just a set number of cylinders, DSF monitors all of them. General Motors thinks the system might be on some of its models in the future.

It's almost impossible not to notice that it's a lot cheaper to fill up at the gas station in the latter portion of this year. As of December 1, the US Energy Information Administration said the average cost of a gallon of gas was $2.778, down almost 50 cents from a year ago. In general, fuel prices have been on the decline for much of 2014, and the effects have started showing themselves with people seemingly more willing to buy lower efficiency vehicles.

The 2015 Ford F-150 is one of the most important US vehicle debuts in years, be it in the pickup segment or the entire marketplace. While we've already known about the truck's engine lineup, its payload ratings and we've even learned a bit about how it drives, the truck's EPA-estimated fuel economy ratings have remained a mystery. The wait is finally over. Ford has announced numbers that put the latest F-150 as the mileage leader among gasoline-powered, full-size pickups in the US, with its new

Five Kg Of Hydrogen And 300-Mile Range Leads To Simple Outcome, We Think

Toyota isn't talking about the Mirai's fuel economy just yet, but that doesn't mean we can't make an educated guess. And we do so by looking at the competition and knowing that the DOE says that "One kg of hydrogen is roughly equivalent to one gallon of gasoline."

UPDATE: Comparing the disparate specification levels on commercial vehicles especially can be bewildering, but as Ram spokesman Nick Cappa points out, the ProMaster City is only offered in long-wheelbase form (unlike the Ford Transit Connect, for example, that starts in short-wheelbase spec). Just which model is the better bargain, then, is up to each customer to decide.

It's expected that Mercedes, like any automaker, aspires to be number one. But we've found a case where being at the top of the list is unlikely to be something of which Daimler is going to boast. That's because we're talking about the automaker most likely to cheat the European fuel economy tests.

Hyundai and sister company Kia are giving themselves a little bit of time to make up a lot of ground in the fight for better fuel economy. We wonder if a recent multi-million fine might have something to do with this public target.

UPDATE: A previous version of this story referred to Ferrari's 7,000 global sales as approaching the 10,000-unit threshold of the CAFE system. This is incorrect, as only US sales contribute towards CAFE totals. Ferrari also offered clarification on the company's CAFE status within Fiat Chrysler's fleet. The post has been edited to reflect this information.

After the huge problems that Hyundai/Kia experienced with its mislabeled fuel economy labels, you'd think that any time an automaker has to adjust its mpg numbers, heralds would be shouting from the rooftops. But, after Ford admitted to three big mistakes with its numbers for the 2013 C-Max Hybrid and Mercedes-Benz had to lower the fuel economy rating for the C-Class, we understand if those heralds are a bit tired by now.

Following the lowering of estimated fuel economy figures from companies like Ford, Hyundai, Kia and even a handful of Mercedes-Benz sedans in the recent past, the Environmental Protection Agency is cracking down by mandating new mileage testing procedures by the end of the year, after first considering some changes months ago. The improved evaluations should make the numbers that buyers see on the window sticker of a vehicle closer to what they experience in the real world.

*UPDATE: Donna Boland, manager of corporate communications at Mercedes Benz USA, told AutoblogGreen that the sticker change only applied to around 500 C-Class vehicles on dealer lots, since a new C-Class came out in late August. "About 500 are left in the United States, and we've relabeled them," she said.

Before even officially going on sale to customers, the GMC Canyon and Chevrolet Colorado midsize pickup twins are already proving to be a success with dealer orders exceeding original projections. Now, there is even more good news for these siblings, with the fuel economy for their four-cylinder engines netting class-leading numbers and the 3.6-liter V6 getting segment-best payload ratings.

With its crazy 707 horsepower on tap and roughly $60,000 starting price, the 2015 Dodge Challenger SRT Hellcat has been one of the most talked about cars of the summer, maybe even the year. However, there's always been one lingering question about the behemoth that Dodge has waited to answer until now – its fuel economy. The EPA ratings for the muscle car are finally out, and the numbers are actually pretty impressive for a vehicle with this much power.

For the most part, plug-in hybrids rely on the power stored in the battery until that charge is depleted. Unless the switch can be changed manually, it's only then that the cars fire up the internal combustion engine and begin using the fossil fuels on board. This is ideal, of course, when one's drive isn't long enough that the car needs to start sipping gasoline at all. On longer commutes, when it's certain that the route is longer than the car's all-electric range, this isn't necessarily the m